Pantoea brenneri AS3 and Bacillus ginsengihumi M2.11 as Potential Biocontrol and Plant Growth-Promoting Agents

— The mechanisms of biocontrol action of the strains Pantoea brenneri AS3 and Bacillus ginsengihumi M2.11 were investigated. The ability of the strains to release ammonium and cyanide ions was established, as well as their cellulase and protease activity and ability to fix nitrogen and to mobilize soil phosphates and phytates. The strains were able to synthesize siderophores, with their maximum production observed 48 h of cultivation reaching 198 ± 8 μM in B. ginsengihumi strain M2.11 and 84 ± 7 μM in P. brenneri strain AS3. The bacteria produced a phytohormone, indoleacetic acid (IAA), with the yields of 34 ± 3 and and 29 ± 2 μg/mL for B. ginsengihumi M2.11 and P. brenneri AS3, respectively, after 24 h of growth. It was found that both strains had fungicidal activity against plant pathogens of the genus Fusarium the growth of different Fusarium species was inhibited by more than 90% in the presence of P. brenneri AS3 or B. ginsengihumi M2.11. It was concluded that the strains P. brenneri AS3 and B. ginsengihumi M2.11, which possess multiple characteristics useful to plants, may be used as objects for creating biofertilizers and plant growth stimulators.